Cowls for air vent pipes



May 5, 1970 Filed July 15, 1968 2 Sheets-Sheet l May 5, 1970 w. TOPP3,509,811

COWLS FOR AIR VENT PIPES Filed July 15, 1968 2 Sheets-Sheet 2 UnitedStates Patent O 3,509,811 COWLS FOR AIR VENT PIPES Wilhelm Topp,deceased, late of Empelde, Germany, by

Rudi Kaulfuss, executor, Eschwege, Germany, assignor to BerndKretzschmer, Hinter den Hofen, Germany Filed July 15, 1968, Ser. No.746,705 Int. Cl. F231 17/02 US. CI. 98-78 14 Claims ABSTRACT OF THEDISCLOSURE BACKGROUND OF THE INVENTION In one existing method ofdrying-out, keeping dry and ventilating roofs consisting of a number oflayers, with or without an air gap between them, small ventilation pipesare incorporated into the roofs, and pass through the outer-mostcovering to the open air. These small tubes or pipes may be providedwith a swan neck, to give a chimney action and enable air to be ventedfrom the roof space below the pipes or from the space between two of theroof coverings, while preventing the entry of moisture such asrainwater, for instance. Alternatively, the upper end of the pipe justprojects above the surface and is ice sages between the lenticular bodyand the closure member.

The vent apertures are formed in the flat end wall of a bucket-shapedmember or tubular body, the said end wall of which extends as a skirtportion beyond the periphery of the bucket-shaped member itself and iscurved downwards.

The lenticular body is spaced above the vent apertures and the curvatureof its faces is approximately the same as that of the skirt portion.

The connection between the lenticular body and the skirt portion is inthe form of radial, streamlined, vertical walls or partition memberswhich extend axially and run inwards from the outer periphery of theskirt portion and the periphery of the lenticular body and terminateoutside the area containing the vent apertures, thus producing a numberof radial flow passages between the lenticular body and the skirtportion.

The vent apertures should preferably be surrounded by annular flanges,so that they open above the general plane of the flat end-wall of thebucket-shaped member.

The slightly tapered bucket-shaped member can be fitted over an air venttube or pipe.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of aventilator cowl constructed according to one embodiment of the presentprovided with one or more nozzle openings in the end SUMMARY OF THEINVENTION The present invention provides a cowl for a vent pipecomprising a closure member for the vent pipe, a plurality of aperturesin the closure member opening in a substantially common plane, theclosure member being at least partly curved downwardly from said planetowards the vent pipe, a lenticular body spaced upwardly from theclosure member and a number of inwardly tapering radially extending flowpassages formed between the lenticular body and the closure member.

The present invention further provides a cowl for a vent pipe comprisinga cylindrical body adapted to fit over the open end of the vent pipe, aclosure member for the cylindrical body having a centrally disposedsubstantially flat circular portion and an outwardly extending skirtportion curved downwardly from the general plane of the central portiontowards the cylindrical body, a plurality of bosses formed on thecentral portion on the face remote from the cylindrical body, aplurality of apertures formed through the central portion and the bossesto open above the general plane of the central portion, a lenticularbody part spaced from the closure member and having that face opposed tothe closure member oppositely curved to the skirt portion but ofsubstantially the same curvature as the skirt portion and a plurality ofinwardly tapering radially extending fiow pasinvention, and

FIG. 2 is a section taken along the line II-II of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT This example of the presentinvention, as can be seen from FIGS. 1 and 2 comprises a slightlytapered tubular body or bucket-shaped member 1 which is closed at thetop by a closure member comprising a centrally disposed substantiallyflat circular portion 2 surrounded by a skirt portion 5.

Vent apertures 3 are provided in concentric rings in the circularportion 2 as is more clearly shown in FIGURE 2. The vent apertures 3extend through locally thickened portions of the central portion 2 onthe face thereof remote from the body 1 so that they are each surroundedby an annular boss 4 and open above the general plane of the centralportion by a distance corresponding to the depth of the annular bosses4. The skirt portion 5 curves downwardly away from the general plane ofthe central portion 2 towards the tubular body 1. Supported on theannular skirt portion 5 are a number of partition members 6, which runfrom the periphery 7 of the skirt portion 5 and terminate with theirinner edges 13 on the periphery of circular portion 2. The partitionmembers 6 which extend radially inwardly are streamlined in section, ascan be seen from FIGURE 2, being thicker in cross-section in thevicinity of the periphery 7 of the skirt portion 5 than at their innerends.

Fixed to the top edges of the partition members 6 is a lenticular body8, the curvature of the opposed faces of which correspond approximatelyto that of the skirt portion 5, so that the cross-section of thepassages 12 between the curved underside 9 of the lenticular body 8 andthe upper face of the skirt portion 5 is reduced continuously from theoutside to the centre. Hence, because of the reduction in cross-section,there is a corresponding increase in velocity as the air flows through.The lenticular body 8 should preferably be hollow and consist of twoseparate curved members 9 and 10 joined together.

As indicated in FIGURE 1, the cowl can be fitted by its taperedbucket-shaped tubular body 1 over the vent pipe 11. The exampleillustrated has 25 vent apertures 3, and 12 partition members 6, whichsupport the lenticular body 8. The number of vent apertures andpartition members 6 can naturally be varied, according to the size ofthe cowl and the use to which it is put.

A plastics such as P.V.C., for example, may well be used for making thecowl.

The cowl here proposed is characterised in particular by highlyeffective air extraction from below the roof covering of hot and coldroofs, with and without heatbarrier layers. Air venting under the steambrake is also possible. When used as a fit-over cowl, the flow passage12 formed in accordance with the invention between the skirt portion 5and the lenticular body 8 results in a particularly marked ejectoraction in the associated vent pipe, so that the cowl is especially goodfor ventilating chemical laboratories, kitchens, store-rooms of allkinds, baths, garages, laundries, lavatories and bathrooms, stables,cattle stalls, containers, tanks and other utilitarian spaces, as wellas for the draught-free ventilation of rail way carriages, omnibuses,closed troop-carrying vehicles, lorry drivers cabins and the like.

i What is claimed is:

1. A cowl for a vent pipe comprising a closure member for the vent pipe,a plurality of apertures in the closure member opening in asubstantially common plane, the closure member being at least partlycurved downwardly from said plane towards the vent pipe, a lenticularbody spaced upwardly from the closure member and a plurality ofsubstantially radially extending partition members disposed between andfixedly attached to said closure member and said lenticular body todefine a number of inwardly tapering radially extending flow passagesformed between the lenticular body and the closure member and openingoutwardly of the cowl substantially throughout the entire outerperiphery thereof.

2. A cowl according to claim 1, in which the closure member has asubstantially flat central portion in which the apertures are formed anda skirt portion extending around the fiat portion which skirt portion isdownwardly curved.

3. A cowl according to claim 2 in which the lenticular body has one facewhich is opposed to the closure member and which has substantially thesame curvature as the skirt portion.

4. A cowl according to claim 1 in which the partition members are ofstreamline cross-section.

5. A cowl according to claim 1 in which the partition members are ofreducing cross-section in the radially inwardly direction considered ina plane normal to the axis of the vent pipe.

6. A cowl according to claim 1 in which the partition members extendinwardly from the edges of the skirt portion and the lenticular body andterminate short of the area of the closure member in which the aperturesare formed.

7. A cowl according to claim 1 in which the closure member provides anend wall for a slightly tapering tubular body adapted to be fitted overthe end of the vent pipe.

8. A cowl for a vent pipe comprising a closure member for the vent pipe,a plurality of apertures in the closure member opening in asubstantially common plane, the closure member being at least partlycurved downwardly from said plane towards the vent pipe, a lenticularbody spaced upwardly from the closure member and a number of inwardlytapering radially extending flow passages formed between the lenticularbody and the closure member, the closure member being provided with anumber of thickened portions through which the apertures extend so thatthe plane to which said apertures open lies above the general plane ofthe closure member.

9. A cowl for a vent pipe comprising a closure member for the vent pipe,a plurality of apertures in the closure member opening in asubstantially common plane, the closure member being at least partlycurved downwardly from said plane towards the vent pipe, a lenticularbody spaced upwardly from the closure member and a number of inwardlytapering radially extending flow passages formed between the lenticularbody and the closure member, each aperture being surrounded by anannular boss extending above the general surface of the closure member.

10. A cowl for a vent pipe comprising a cylindrical body adapted to fitover the open end of the vent pipe, a closure member for the cylindricalbody having a centrally disposed substantially flat circular portion andan outwardly extending skirt portion curved downwardly from the generalplane of the central portion towards the cylindrical body, a pluralityof bosses formed on the central portion on the face remote from thecylindrical body, a plurality of apertures formed through the centralportion and the bosses to open above the general plane of the centralportion, a lenticular body part spaced from the closure member andhaving that face opposed to the closure member oppositely curved to theskirt portion but of substantially the same curvature as the skirtportion and a plurality of inwardly tapering radially extending flowpassages between the lenticular body and the closure member.

11. A cowl according to claim 10 in which the flow passages are definedby radially extending partition members between the closure member andthe lenticular body.

12. A cowl according to claim 11 in which the partition members extendradially inwardly from the peripheries of the lenticular body and theclosure member and terminate at the circumference of the circularportion of the closure member.

13. A cowl according to claim 11 in which the partition members are ofinwardly tapering thickness.

14. A cowl according to claim 11 in which the flow passages have aninwardly tapering cross-section considered both in a plane normal to theaxis of the tubular body and in a plane containing the axis of thetubular body.

References Cited UNITED STATES PATENTS 697,125 4/ 1902 Anderson 93783,302,552 2/1967 Walsh 9878 XR 3,345,931 10/1967 Walsh 98-78 MEYERBERLIN, Primary Examiner US. Cl. X.R. 98-122. 83

